protein kinase C conserved region 1 (C1 domain) found in the GEM-interacting protein (GMIP)-like family
The GMIP-like family includes GMIP, Rho GTPase-activating protein 29 (ARHGAP29) and Rho GTPase-activating protein 45 (ARHGAP45). GMIP is a RhoA-specific GTPase-activating protein that acts as a key factor in saltatory neuronal migration. It associates with the Rab27a effector JFC1 and modulates vesicular transport and exocytosis. ARHGAP29, also called PTPL1-associated RhoGAP protein 1 (PARG1) or Rho-type GTPase-activating protein 29, is a GTPase activator for the Rho-type GTPases by converting them to an inactive GDP-bound state. It has strong activity toward RHOA, and weaker activity toward RAC1 and CDC42. ARHGAP29 may act as a specific effector of RAP2A to regulate Rho. In concert with RASIP1, ARHGAP29 suppresses RhoA signaling and dampens ROCK and MYH9 activities in endothelial cells and plays an essential role in blood vessel tubulogenesis. ARHGAP45, also called minor histocompatibility antigen HA-1 (mHag HA-1), is a Rac-GAP (GTPase-Activating Protein) in endothelial cells. It acts as a novel regulator of endothelial integrity. ARHGAP45 contains a GTPase activator for the Rho-type GTPases (RhoGAP) domain that would be able to negatively regulate the actin cytoskeleton as well as cell spreading. However, it also contains N-terminally a BAR-domin which can play an autoinhibitory effect on this RhoGAP activity. Members of this family contain a zinc-binding C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.